Geometric and Arithmetic Sequences

Find the 9th term in the following geometric sequence:

4, 8, 16, 32, ...

• 384

• 512

• 768

• 1,024

Carey is organizing her books and putting them on shelves. She put 2 books on the first shelf, 8 books on the second shelf, 32 books on the third shelf, and 128 books on the fourth shelf. What kind of sequence is this?

• Geometric

• Arithmetic

• Both

• Neither

Given the geometric sequence 1, 5, 25, 125, ..., write an explicit formula.

What is the common difference of the sequence 2, -1, -4, -7,...?

• -3

• -1

• -2

• 3

An arithmetic sequence is given below.

2, 9, 16, 23, ...

Which is the explicit formula for the n^th term a_n?

• a_n = -7n+9

• a_n = 7n-5

• a_n = 7n-9

• a_n = -7n+5

What is the 67^th term of the following arithmetic sequence.

• -445

• 67

• 625

• 607

Find the common difference: 29, 21, 13, 5, ...

• d = -10

• d = -9

• d = -8

• d = -7

Write the explicit equation for the geometric sequence: 15, 45, 135, . . . ?

Find the 6th term of the following geometric sequence:

2, 8, 32, 128, ...

• 8192

• 2048

• 512

• 128

Identify the common difference.
97, 86, 75, 64, ...

• 8

• 11

• -11

• -8